Rotary/push operating devices for data input via a so-called human-machine interface in a vehicle and/or for operating units of a vehicle are known in prior art. Normally, a rotary/push operating device is provided with a rotary/push operating element. By rotating the rotary/push operating element letters, signs or functions are selected and acknowledged by pressing said element. After acknowledgement of such an input a task corresponding to the input is performed.
From DE-A-102 61 284 a rotary operating element is known which is adapted to be moved along its rotary axis when a force acts upon said element. This operating element comprises a toothed portion which is in engagement with a gear wheel to transmit the rotation of the operating element to the gear wheel. The rotary axis of the gear wheel is arranged in parallel to and sideways of the rotary axis of the operating element. This measure allows the operating element to be moved along its rotary axis. The toothed portion itself preferably forms a gear wheel such that a full rotation of the operating element is possible.
Further, in prior art, rotary/push operating devices are known where the rotary/push operating element comprises a central key or a plurality of central keys normally secured against rotation which are arranged inside the rotatable rotary element. These keys are adapted to be depressed and serve for data input and/or acknowledgement of data input. However, the rotary operating element itself is not adapted to be depressed. Examples of the above described prior art rotary/push operating devices are disclosed in DE-A-10 2006 018 518, DE 10-A-2004 054 178, DE-A-199 64 131, DE-A-101 37 883, EP-B-0 282 817 and GB-A-2 186 668.